Compounds having general formula (I) are well-known in the art as comonomers for the preparation of crystalline liquid polyesters and their synthesis is described in Chemical Abstracts, vol. 97, No. 72969, 1982, in Chemical Abstracts, vol. 99, No. 218533, 1983 and in Makromolecular Chemistry, Rapid Commun., 6, 209, 1985.
In these references the Ar' radical represents substituted phenyl groups in various positions or substituted naphthalene groups in position 2,6 Ar is invariably a substituted phenyl group in position 1,4 and R represents a hydrogen atom or methyl radical.
U.S. Pat. No. 4,695,649 describes the preparation of di-(p-benzyloxycarbonylphenyl)isophthalate, and its repellent action with respect to insects, and the preparation of di-(p-octyloxycarbonylphenyl) isophthalate and its use as a plasticizer with respect to polyamides.